tempo_plot_means: Plot predicted mean transition times
In vlandau/tempo: Temporally-Explicit Models for Phenological Observations

This function plots the posteriors of mean transition times for observations included in the output from tempo_derive() (specified using the obs_idx argument to tempo_derive). In order to use this function, the quantity argument needs to include "mean" at the time that tempo_derive() was called.

1	tempo_plot_means(x, x_lim = NULL, y_axis_order = NULL)

`x`	output from `tempo_derive()`. `tempo_derive()` needs to have been called with the `quantity` argument equal to or containing `"mean"`.
`x_lim`	optional; A vector of length two of lower and upper bounds for the x axis. Defaults to null, in which case the min and max of the data are used to generate the x axis limits.
`y_axis_order`	optional; a vector of observation IDs specifying the order in which they should be plotted. Defaults to `NULL`, in which case ascending alphanumeric order is used.